文件函数fread

#include<stdio.h>
#include<stdlib.h>
struct student
{long int num;
 char name[20];
 char major[25];};
FILE *fp;
main()
{int i,num,realnum;
 struct student st,*pst;
printf(“input student number:”);
scanf(“%d”,&num);
pst=(struct student *)malloc(num*sizeof(st));
if(!pst)
   return;
fp=fopen(“f:\\18.txt”,”rt”);
if(NULL==fp)
   {free(pst);return;}
realnum=0;
printf(“%s\t%s\%s\%s\n”,”number”,”name”,”major”);
for(i=0;i<num&&(!feof(fp));i++)
  {fread(pst+i,sizeof(struct student),1,fp);
   realnum++;
   st=*(pst+i);
   printf(“realnum=%d\n”,realnum);
  printf(“%ld\t%s\t%s\n”,st.num,st.name,st.major);
  }
  free(pst);fclose(fp);
  }